Acute Sleep Restriction Affects Sport-Specific But Not Athletic Performance in Junior Tennis Players

Mental Fatigue Impairs Second Serve Accuracy in Tennis Players

Purpose: The aim of this 2-week randomized, counterbalance and crossover study was to investigate the effect of acute mental fatigue (MF) on tennis serve performance and accuracy in tennis players. Methods: Ten male tennis players (18 ± 4 years, 1.80 ± 0.08 m; 71 ± 13 kg) were randomized to either the MF group (N = 5) that underwent an acute MF protocol or to a control (CON) group (N = 5). The MF condition consisted in a 30-min modified Stroop color word task performed before on-court serve speed test. A visual analogue scale (VAS) was used to assess the perceptions of MF and motivation toward the upcoming technical tests. Results: Reduction over baseline score of Stroop test was noted in accuracy (N < .001), but not in reaction time (N = .968) in the MF group. Increments in perceived workload were detected (N < .001) in MF group compared to CON. No differences for first and second serve speed from deuce and advantage side were observed. Increment of percentage of failed second serves from the deuce side (N = .043) in MF were detected. Conclusions: An acute MF protocol reduced tennis serve accuracy from deuce side in male tennis players. Players should avoid cognitive efforts before training sessions and matches to prevent negative effects of their technical performance.

To Sleep Dreaming Medals: Sleep Characteristics, Napping Behavior, and Sleep-Hygiene Strategies in Elite Track-and-Field Athletes Facing the Olympic Games of Tokyo 2021

PURPOSE

Few data are available on sleep characteristics of elite track-and-field athletes. Our study aimed to assess (1) differences in sleep between sexes and among different track-and-field disciplines, (2) the effect of individualized sleep-hygiene strategies on athletes' sleep parameters, and (3) daytime nap characteristics in track-and-field athletes.

METHODS

Sleep characteristics of 16 elite Olympic-level track-and-field athletes (male: n = 8; female: n = 8) were assessed during the preseason period, at baseline (T0), and during the in-season period, after the adoption of individualized sleep-hygiene strategies (T1). Sleep parameters were objectively monitored by actigraphy for a minimum of 10 days, for each athlete, at both T0 and T1. A total of 702 nights were analyzed (T0 = 425; T1 = 277).

RESULTS

Female athletes displayed better sleep efficiency (88.69 [87.69-89.68] vs 91.72 [90.99-92.45]; P = .003, effect size [ES]: 0.44), lower sleep latency (18.99 [15.97-22.00] vs 6.99 [5.65-8.32]; P < .001, ES: 0.65), higher total sleep time (07:03 [06:56-07:11] vs 07:18 [07:10-07:26]; P = .030, ES: 0.26), earlier bedtime (00:24 [00:16-00:32] vs 00:13 [00:04-00:22]; P = .027, ES: 0.18), and lower nap frequency (P < .001) than male athletes. Long-distance runners had earlier bedtime (00:10 [00:03-00:38] vs 00:36 [00:26-00:46]; P < .001, ES: 0.41) and wake-up time (07:41 [07:36-07:46] vs 08:18 [08:07-08:30]; P < .001, ES: 0.61), higher nap frequency, but lower sleep efficiency (88.79 [87.80-89.77] vs 91.67 [90.95-92.38]; P = .013, ES: 0.44), and longer sleep latency (18.89 [15.94-21.84] vs 6.69 [5.33-8.06]; P < .001, ES: 0.67) than athletes of short-term disciplines. Furthermore, sleep-hygiene strategies had a positive impact on athletes' total sleep time (429.2 [423.5-434.8] vs 451.4 [444.2-458.6]; P < .001, ES: 0.37) and sleep latency (14.33 [12.34-16.32] vs 10.67 [8.66-12.68]; P = .017, ES: 0.19).

CONCLUSIONS

Sleep quality and quantity were suboptimal at baseline in Olympic-level track-and-field athletes. Large differences were observed in sleep characteristics between sexes and among different track-and-field disciplines. Given the positive effect of individualized sleep-hygiene strategies on athlete's sleep, coaches should implement sleep education sessions in the daily routine of top-level athletes.

Corrigendum: The relationships of sleep duration and inconsistency with the athletic performance of collegiate soft tennis players

[This corrects the article DOI: 10.3389/fpsyg.2022.791805.].

How do patients sleep after orthopaedic surgery? Changes in objective sleep parameters and pain in hospitalized patients undergoing hip and knee arthroplasty

PURPOSE

The aim of this observational cohort study was to assess actigraphy-based sleep characteristics and pain scores in patients undergoing knee or hip joint replacement and hospitalized for ten days after surgery.

METHODS

N=20 subjects (mean age: 64.0±10.39 years old) wore the Actiwatch 2 actigraph (Philips Respironics, USA) to record sleep parameters for 11 consecutive days. Subjective scores of pain, by a visual analog scale (VAS), were constantly monitored and the following evaluation time points were considered for the analysis: pre-surgery (PRE), the first (POST1), the fourth (POST4), and the tenth day (POST10) after surgery.

RESULTS

Sleep quantity and timing parameters did not differ from PRE to POST10, during the hospitalization whereas sleep efficiency and immobility time significantly decreased at POST1 compared to PRE by 10.8% (p=0.003; ES: 0.9, moderate) and 9.4% (p=0.005; ES: 0.86, moderate) respectively, and sleep latency increased by 18.7 min (+320%) at POST1 compared to PRE (p=0.046; ES: 0.70, moderate). Overall, all sleep quality parameters showed a trend of constant improvement from POST1 to POST10. VAS scores were higher in the first day post-surgery (4.58 ± 2.46; p=0.0011 and ES: 1.40, large) compared to POST10 (1.68 ± 1.58). During the time, mean VAS showed significant negative correlations with mean sleep efficiency (r = -0.71; p=0.021).

CONCLUSION

Sleep quantity and timing parameters were stable during the entire hospitalization whereas sleep quality parameters significantly worsened the first night after surgery compared to the pre-surgery night. High scores of pain were associated with lower overall sleep quality.

Wavelet-Based Multiscale Decomposition Algorithm for Trajectory Capture of Tennis Serves

Tennis is a sport that is enjoyed by young and old alike. Participants can decide the style of play and control the speed and spin of the ball according to their ability, so the physical demands on participants are not high and the amount of exercise can be effectively controlled. With the increasing demand for quality of life, the population of tennis is growing rapidly. People have taken up tennis as a form of recreation. For professional players, the serve, as the foundation of the introduction to tennis, has been a challenge. A good serve can effectively control the situation on the court and even turn defeat into victory. Therefore, this paper focuses on capturing tennis trajectories using multidimensional wavelet segmentation in an attempt to provide an effective reference for tennis. The results show that our method has a good trajectory capturing effect and can correct and guide the tennis serving action well.

The Impact of a 14-Day Altitude Training Camp on Olympic-Level Open-Water Swimmers' Sleep

Despite the common belief that sleep quality at altitude is poor, the scientific evidence to support this notion is still modest. Therefore, the purpose of the present study was to evaluate possible changes of actigraphy-based and subjective sleep parameters in a group of elite open-water swimmers during a 14-day altitude training camp (ATC) at 1500 m. The study subjects were five Olympic-level open-water swimmers (mean age: 25.0 ± 3.2 years; 3 females and 2 males). All subjects wore a wrist activity monitor and filled a sleep diary for 18 consecutive nights, 4 nights before and 14 nights during ATC. The data were then analyzed at four different time points: before ATC (PRE), the first two days of ATC (T1), and after one (T2) and two weeks of ATC (T3). Training load, assessed as the covered distance (km), session rating of perceived exertion (sRPE), and heart rate (HR), was monitored during the week before and the first and second week of ATC. No significant differences in objective and subjective scores of sleep quality were detected, whereas the sleep onset time (p = 0.018; η2p = 0.83, large) and sleep offset time (p < 0.001; η2p = 0.95, large) significantly differed among PRE, T1, T2, and T3: elite athletes started to sleep and woke up ≃ 1 h earlier the first two days of ATC compared to PRE (sleep onset time: p = 0.049; sleep offset time: p = 0.016). Further, an increase in the training volume during the two weeks of the ATC was observed, with the most time spent in a low-intensity regime and an increase in time spent in a high-intensity regime compared to PRE. Sleep quality was not negatively influenced by a 14-day altitude training camp at 1500 m in a group of Olympic-level elite swimmers despite an increase in perceived exertion during training sessions. Nonetheless, early sleep onset and sleep offset times were observed for the first two nights of ATC: elite athletes started to sleep and woke up ≃ 1 h earlier compared to the baseline nights.

The Relationships of Sleep Duration and Inconsistency With the Athletic Performance of Collegiate Soft Tennis Players

We evaluated the relationships of daily sleep duration and inconsistency with soft tennis competitive performance among 15 healthy collegiate soft tennis players (13 male, 2 female, mean age = 19.7 ± 0.8 years, height = 170.8 ± 7.3 cm, weight = 60.3 ± 5.6 kg, soft tennis experience = 8.7 ± 2.0 years). Sleep duration and inconsistency were determined by a 50-day sleep diary, which recorded sleep and wake times of sleep. Soft tennis athletic performance was evaluated by a service and baseline stroke accuracy test and the spider run test. Mean sleep duration was 7.4 ± 1.7 h. No correlation was found between long-term mean sleep duration and athletic performance. But inconsistency in sleep duration (SD of sleep duration) was inversely correlated with service score after controlling for soft tennis experience and sex (r = −0.56, p = 0.046). There was no significant relationship between sleep inconsistency and other athletic performance. This result indicates that reducing the instability of sleep duration (i.e., sleep regular hours) in the long-term may have a positive effect on soft tennis players’ service performance. Although participants’ current mean sleep duration (7.4 h) was not as sufficient as the recommendation in sleep extension experiments (9–10 h), it revealed the importance for athletes to maintain regular sleep in daily life.

Sleep Architecture in Response to a Late Evening Competition in Team-Sport Athletes

Purpose: The aim of this study was to assess the effect of a late evening competition on sleep characteristics and perceived recovery in team-sport players using a validated self-applicable and portable polysomnographic device. Methods: Sixteen team-sport players (age: 25.4 [1.4] y; body mass index: 23.6 [0.5] kg/m2) completed the study. Objective and subjective sleep data were collected for 4 consecutive nights: 2 nights before (PRE2 and PRE1) and the 2 nights after an evening match (POST1), performed between 6:00 PM and 9:00 PM. Total quality of recovery values were also collected in the morning. Results: A significantly delayed bedtime (P < .0001; , large) was observed in the first night after the competition (2 h 29 min [1 h 15 min]) compared both to PRE2 (+88 min; P < .0001), PRE1 (+98 min; P < .0001), and POST1 (+100 min; P < .0001), and similar results were observed for wake-up time (P = .033; , large): Players woke up significantly later in evening match (9 h 20 min [1 h 55 min]) compared with PRE2 (+85 min; P = .050) and POST1 (+85 min; P = .049). Conversely, total sleep time; sleep efficiency; sleep onset latency; wake after sleep onset; cortical arousals; N1, N2, N3, and REM (rapid eye movement) percentages; total quality of recovery values; and scores of subjective sleep quality did not vary among the 4 study nights. Conclusions: Team-sport players had delayed bedtime and wake-up time following an evening competition; however, sleep quality, duration, and subjective scores of recovery were not affected by the evening match. The delayed wake-up time seems to protect athletes’ sleep efficiency/duration against the evening-match-induced delayed bedtime.

Are elite track and field athletes on track? The impact of COVID-19 outbreak on sleep behavior and training characteristics

The Covid-19 outbreak forced many governments to enter a nationwide lockdown. The aim of this study was to evaluate, by means of a survey, changes in sleep parameters and physical activity characteristics of elite track and field athletes in three periods: before the lockdown (T0), during the lockdown (09th March – 03rd May 2020, T1) and the first month after the lockdown (T2). This study was conducted from May 2020 to June 2020 and data were collected using an offline survey with 89 elite track and field athletes (mean age: 24.7 ± 5.4; n = 43 males; n = 46 females). The survey consisted of demographic data and questions on physical activity and sleep behavior at T0, T1 and T2. Athletes reported lower sleep quality scores at T1 compared to T0 and T2 (p < 0.0001) and registered delayed bedtime, wake-up time and longer sleep latency during the lockdown compared to pre-lockdown and post-lockdown whereas no changes in total sleep time were reported. No inter-group differences were detected in sleep characteristics between short- and long-term disciplines and between genders. The weekly training volume decreased from 16.1 ± 5.7 hours at T0 to 10.7 ± 5.7 hours at T1 (p < 0.0001) whereas no significant differences were detected in training volume during the lockdown in relation to the square footage of the house (p = 0.309). Alcohol (p = 0.136) and caffeine intake (p = 0.990) and use of electronic devices (p = 0.317) were similar pre-, during, and post-lockdown. The unprecedented circumstances of the Covid-19 pandemic had negative impacts on the Italian track and field athletes’ sleep and training volumes.

Does observance of Ramadan affect sleep in athletes and physically active individuals? A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis is to provide an accurate description of the effect of Ramadan observance on sleep duration, sleep quality, daily nap duration, and daytime sleepiness in athletes and physically active individuals. Five electronic databases (PubMed, Web of Science, Scopus, Wiley, and Taylor and Francis) were used to search for relevant studies conducted with athletes or physically active individuals during Ramadan, published in any language, and available before May 23, 2021. Studies that included assessments of sleep quantity and/or quality, and/or daytime sleepiness, and/or daily naps in athletes and physically active individuals were included. The methodological quality of the studies was assessed using "QualSyst". Of the 18 papers included in this study (298 participants in total), 14 were of strong quality, two were moderate, and the remaining two were rated as weak. Individuals who continued to train during Ramadan experienced a decrease in sleep duration (number of studies, K = 17, number of participants, N = 289, g = -0.766, 95% confidence interval [CI] -1.199 to -0.333, p = 0.001). Additionally, the global score of the Pittsburgh Sleep Quality Index increased from 4.053 (K = 5, N = 65, 95% CI 3.071-5.034) pre-Ramadan, to 5.346 (95% CI 4.362-6.333) during Ramadan, indicating a decrease in sleep quality. The duration of daytime naps increased during compared to pre-Ramadan (K = 2, N = 31, g = 1.020, 95% CI 0.595-1.445, p = 0.000), whereas Epworth Sleepiness Scale scores remained unchanged during versus pre-Ramadan (K = 3, N = 31, g = 0.190, 95% CI -0.139-0.519, p = 0.257). In conclusion, individuals who continued to train during Ramadan experienced a decrease in sleep duration, impairment of sleep quality, and increase in daytime nap duration, with no change in daytime sleepiness levels.